This is just in our little corner of the Milky Way, but not thought to be the result of just one supernova. I last looked into this about a decade ago so I might be behind the times, but at that time the most popular theory was that the cloud that became our Solar System was the result of thousands of supernova scattering and mixing atoms, across both the first two generations of stars (the Sun is considered to be a third-generation star), and that mixing is thought to be an important factor in making it complex enough to have rocky inner planets, gaseous outer planets, etc.